Rafael Nadal has certainly been in fighting mood in the last few weeks. On the court, the 14-time Grand Slam champion has shown signs of returning to his elite form, winning tournaments in Monte Carlo and Barcelona ahead of his attempt to win a 10th French Open in Paris starting next month. Off the court, he has hit back at doping allegations made by former French health and sports minister Roselyne Bachelot.

In the wake of Maria Sharapova’s positive test for banned substance meldonium at the Australian Open in January, there has been widespread chatter about the scale of drug use in tennis. Last month, Bachelot charged that Nadal’s absence from competition for seven months at the end of 2012 was “certainly due to a positive doping test.”

The comment prompted Nadal to file a lawsuit against the former government minister. The Spaniard has also written a letter to tennis’ governing body, the International Tennis Federation (ITF), instructing them to make the results of all his drug tests public, while firing back against unsubstantiated allegations.

“It can’t be free any more in our tennis world to speak and to accuse without evidence,” read the letter. “Please make all my information public, please make public my biological passport and my complete history of anti-doping controls and tests. From now on I ask you to communicate when I am tested, and the results, as soon as they are ready from your labs.”

The ITF has since responded to Nadal’s letter by confirming he has never failed a drug test, while stating that Nadal is able to release the results of his own drug tests whenever he wants.

There have been differing opinions within the tennis world on the scale of drug use in the sport. While Nadal and world No. 1 Novak Djokovic have said they believe the sport is clean, world No. 2 Andy Murray stated he has had suspicions about players who “don’t seem to be getting tired.”

Nadal and his legions of fans must certainly be hoping the issue does not present a distraction at a time when he's effectively breaking out of long and pronounced slump. The world No. 5’s victory in Monte Carlo earlier this month was his first Masters 1000 title, the most prestigious nine tournaments on the ATP Tour, in close to two years. Making it more impressive, the title was secured through wins over Murray and defending French Open champion Stan Wawrinka. And Nadal then followed up that triumph by winning a ninth title in Barcelona, after defeating two-time defending champion Kei Nishikori in the final on Sunday.

The victory in Barcelona was also Nadal’s 49th clay-court title, equaling the record held by Guillermo Vilas. His performances at the start of the European clay-court season, winning all 10 matches to date, have also put the Mallorca native firmly in the running to reclaim the French Open and add to his already record collection of nine titles.

Nadal has made it clear how much he is enjoying his return to success. And he has every reason to take it all in after struggling through a 2015 season that was his worst in a decade, followed by a poor start to 2016, in which he suffered a first-round loss at the Australian Open. He had even been dethroned as the King of Clay, having last year failed to win a clay-court title heading into the French Open for the first time since 2004 and then being brushed aside by Djokovic in the quarterfinals at Roland Garros.

With Djokovic in imperious form and as dominant a world No.1 as there has been in some time, Nadal’s prospects of regaining the French Open looked slim. But he is now providing a powerful response to those who had written him off, and trails just Djokovic as the favorite to win in Paris. And whether on or off the court, Nadal is set to continue to be a prominent figure in the tennis world for some time yet.